Oral-History:William Stotz
About William Stotz
William Stotz was born in Pittsburgh, PA on October 13th, 1926. Stotz would become a very important engineer in the field of radar, radio, and military defense systems. He worked at Bendix, where he was involved with ground radar and surveillance radar systems for the military. Stotz also worked at IBM with the SAGE Computer system.
In this interview, Stotz talks about his initial curiosity with engineering, his involvement in several groundbreaking engineering projects, and his work in many important radio and surveillance systems.
About the Interview
WILLIAM STOTZ: An Interview Conducted by Frederik Nebeker, IEEE History Center, 13 October 2010
Interview # 551 for the IEEE History Center, The Institute of Electrical and Electronics Engineers Inc.
Copyright Statement
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It is recommended that this oral history be cited as follows:
Bill Stotz, an oral history conducted in 2010 by Frederik Nebeker, IEEE History Center, Piscataway, NJ, USA.
Interview
INTERVIEW: William Stotz
INTERVIEWER: Frederik Nebeker
DATE: 13 October 2010
PLACE: The National Electronics Museum, Baltimore, Maryland
Background and Education
Nebeker:
This is the 13th of October, 2010. I'm talking with Bill Stotz at the National Electronics Museum. This is Frederik Nebeker. Could we begin with where and when you were born?
Stotz:
I was born in Pittsburgh October 13th, 1926.
Nebeker:
My goodness. Happy birthday.
Stotz:
It's just a coincidence.
Nebeker:
What did your father do?
Stotz:
He was an electrical engineer. He designed motors and generators for railway equipment for Westinghouse.
Nebeker:
Did you have siblings?
Stotz:
Yes, I had an older brother.
Nebeker:
And you lived in Pittsburgh?
Stotz:
No, we left Pittsburgh when I was 9-years-old. My brother was a mechanical engineer who worked all of his life for Grumman.
Nebeker:
So were you interested in technology from an early age?
Stotz:
Yes, I would say so. I was exposed to it.
Nebeker:
Did you grow up thinking you would be an engineer?
Stotz:
I probably didn't think of anything else I might do.
Nebeker:
Did you have crystal radio?
Stotz:
I never built a crystal radio. My brother did. He was into that sort of thing more than I was.
Nebeker:
Where did you move after Pittsburgh?
Stotz:
I went to Beloit, Wisconsin. My father got a job there doing the same sort of thing for Fairbanks Morse.
Nebeker:
Did you stay there through high school?
Stotz:
No. My father was a reserve officer in the Army. He was called to active duty, so I spent the second half of my sophomore year in high school in Cambridge, Massachusetts. Then I went to a private school for the last two years.
Nebeker:
This was in World War II?
Stotz:
Yes, in 1942.
Nebeker:
Did he work as electrical engineer for the military?
Stotz:
They saw that he had a engineering degree, so they sent him to the radar school at Harvard and MIT.
Nebeker:
Oh, what a place to be!
Stotz:
Well, except that when he got his engineering degree, there was no electronics. So he had to struggle a bit. But he was a senior officer there, so they made him the commanding officer. He was there off and on with some other jobs in Cambridge. Then he was pulled out of that and he finished the school and they found they had no use for a colonel that had been through that school, so they found other things for him to do. Then they sent him back as commanding officer again. So he was in Cambridge, he was in Washington, and then he was in Philadelphia.
Nebeker:
Did you finish high school in Cambridge?
Stotz:
No, for the last two years of high school I went to a private boarding school in Pennsylvania. I graduated from there in 1944.
Nebeker:
You went to Michigan because it had a good engineering school?
Stotz:
Yes.
Nebeker:
Did you have any connection with Michigan before that?
Stotz:
No, not at all.
Nebeker:
How was your training at Michigan? This was the electrical engineering department I assume?
Stotz:
Yes. I think it was good. It was thorough. I think it gave you a good idea of what engineering is all about.
Nebeker:
Those must have been interesting years. I suppose many of the GI Bill people would be arriving after the war.
Stotz:
Yes, they were. I actually started during the war and there were a lot of Army ASTP and Navy V-5 people the first year or so. In fact, Michigan adopted the ASTP curriculum for everybody.
Nebeker:
Did you decide as an undergraduate to go in a certain direction in electrical engineering?
Stotz:
Well, I knew I was more interested in electronics than I was in power.
Nebeker:
Did they have many courses in electronics?
Stotz:
Yes, they had a good many. They had all of the standard courses, plus a number of graduate courses.
Working at Bendix on Radar
Nebeker:
And how did it go when you graduated?
Stotz:
Well, then I got a job at Bendix. I came here in the summer of '48.
Nebeker:
How did that come about?
Stotz:
Before I left school, I had gotten an offer from Boeing. And I thought I'd see what else there might be around. So I went on a tour of several companies and Bendix offered me a job that sounded a lot more interesting than the one at Boeing. So I came here.
Nebeker:
Was that Boeing in the Seattle area?
Stotz:
Yes.
Nebeker:
That was for electronics I assume?
Stotz:
No, that was for wiring airplanes.
Nebeker:
And the Bendix job was for what?
Stotz:
Bendix had gotten three large radar contracts that summer, and they hired 50 junior engineers.
Nebeker:
That does sound more exciting than wiring airplanes.
Stotz:
Yes, much. And they suddenly needed a lot of people.
Nebeker:
I see. So how was it moving out here and starting with Bendix?
Stotz:
Oh, it was interesting, nothing particularly special about it.
Nebeker:
So you got going on a radar project?
Stotz:
Yes.
Nebeker:
What was that?
Stotz:
CPN 18. That's a S-band search radar, aircraft surveillance.
Nebeker:
So a ground radar, surveillance radar?
Stotz:
[Interposing] Yes.
Nebeker:
For whom?
Stotz:
For the Air Force. And we built about 50 of them, give or take.
Nebeker:
What was your role?
Stotz:
Originally I was the junior engineer on the transmitter and the wave guide components. And before I was through, I had been involved with the modulator and with the MTI receiver to a small degree, which was built by somebody else.
Nebeker:
Was that a successful project?
Stotz:
Yes, we built and installed about 50 of them. And as far as I know, the Air Force was happy with them.
Nebeker:
And how did you like the work at Bendix?
Stotz:
Oh, I found it interesting and it felt a little dull at times, but like any job, you get some dull and some interesting.
Nebeker:
But not dull enough that you were looking elsewhere for a job?
Stotz:
No. I always had the idea that maybe I should be looking, but there was never a good reason at any given time so I never really did.
SPN-8 Radar
Nebeker:
I see in that you worked on the SPN-8 radar?
Stotz:
Yes, that was the next assignment I had. That is an aircraft carrier precision approach system. It's like a GCA, except it's carrier, not ground.
Nebeker:
So a quite different type of radar from the one you had worked on.
Stotz:
Yes, it's X-band. Probably the most interesting thing about it is the stabilized antenna. The antenna has to be aligned properly regardless of what the ship is doing. So there's a very elaborate servo system to make that happen.
Nebeker:
Do you use gyroscopes in that?
Stotz:
Well, you use the ship's vertical, which comes from the ship's gyros. And the antenna was mounted in a bucket, which had a motor and scan mechanism to scan it 100 degrees. And that was hung in a gimbal, which was hung in a pair of uprights. And there are servos to keep the scan shaft vertical.
Nebeker:
So you had some sensor for the verticality of that?
Stotz:
Well, that was the ship's gyro. There is a signal piped around any ship called the ship's vertical. It's just there like the AC power. And you can always use that as a vertical reference for anything.
Nebeker:
So you designed these servos to appropriately turn the base?
Stotz:
Right.
Nebeker:
What was your particular role on that radar?
Stotz:
Well, I got into the middle of it at first when the engineer working on the receiver left and I took over the receiver system, which I knew little about at the time. And then I got involved somewhat in the testing of the gyros or the servo system for the antenna. That was built by a subcontractor.
Nebeker:
Was that a challenging project?
Stotz:
Yes, it was. The first challenge was that I had to learn about receivers instead of transmitters.
Nebeker:
And how was the success of that radar?
Stotz:
We built about 50 of them and installed them on all the carriers the Navy had at the time.
Nebeker:
Oh. Well, that's quite a success if it became the standard on those carriers. Were you involved in installation?
Stotz:
No. I didn't have anything to do with the installation.
Nebeker:
But were you involved in all phases of the design and the development and testing of these radars?
Stotz:
Yes, I worked on the development of the parts that I was involved with, making the engineering model work and then following that all the way through the production phase.
Nebeker:
And testing the first production models?
Stotz:
Yes. We followed the production tests very closely in the beginning. And there were always problems that always came back to us.
Nebeker:
But nothing you couldn't solve.
Stotz:
Not that I can remember.
SDV Radar
Nebeker:
So the next project was the SDV radar?
Stotz:
In the SAGE system, there are long-range radars and there are gap-filler radars. The gap fillers are S-band surveillance radars, not unlike the CPN-18. And the video data had to be transmitted back to the computer center over phone lines, so they devised a way of slowing it down. That SDV stands for Slowed-Down Video.
Nebeker:
In order to match the bandwidth of the telephone line?
Stotz:
Yes, by using an electrostatic storage tube that has a raster in the tube. You write successive dots following the high-speed scan of the radar. Then you read them at a much lower rate that can be transmitted over the phone line. In the process, since you're writing fast, you're building up charge on these spots and you get a certain amount of video integration, which helps the noise problem.
Nebeker:
Was this like television technology?
Stotz:
Yes. It is a raster. I believe it was 256 bits. Again, this was a thing designed by somebody else originally. Lincoln Lab developed this system. And they hired us to build five prototypes.
Nebeker:
Was this for the SAGE program from the beginning?
Stotz:
Yes, when the SAGE program was in its early development stages. But we lost the production contract after building those five.
Nebeker:
That sounds like quite different work.
Stotz:
Completely different.
Nebeker:
Did you like the challenges involved there?
Stotz:
Well, again, it was a whole new technology. I didn't even know what it was until we were about done with the project. It was digital hardware, and you had to know something about logic design, which I had never heard of. We had this one circuit board with I think had 32 resistors and 96 diodes on it, and I didn't really know what it was. It turned out it was two AND gates for switching the deflection signals on the tube from the write side to the read side and back. Well, I'd never heard of an AND circuit. So that was very interesting. But unfortunately we had no production on that.
SAGE System and IBM
Nebeker:
Did you have other work on the SAGE system?
Stotz:
We got a contract from IBM at one point to build a display for the gap filler—the S-band radars—which was intended to allow an operator to blank out ground clutter. That's sort of a peculiar process, but we had a contract to build these things. We designed it and IBM didn't like the design, so they canceled the contract. Not very many months later, we got another contract from IBM to build the entire input interface to the SAGE system computer. I think the Air Force was a little bit concerned about some of the things IBM was doing and they got us involved. And so we then got a contract for the whole thing from the right side of the magnetic drum storage back to the telephone lines.
Nebeker:
So you were taking all of this radar data in and feeding into the SAGE computer. What was involved in that?
Stotz:
For one thing, it included these indicators that we had been shut down on before.
Nebeker:
But you had that experience behind you.
Stotz:
And it also included all of the stuff for the long-range data that was coming in on the phone lines and I don't remember what all else. Anyway, it was the whole input side of the computer.
Nebeker:
Well, again, it's a different technology—all of this data processing and handling.
Stotz:
Here we were working on the IBM design. In other words, we had to use their modules. It was a modular system where they had pluggable units with about eight tubes on them, all different kinds of them. And you had to use those.
Nebeker:
They didn't have suitable transistors at the time?
Stotz:
No. The computer was about as powerful as anything that existed at that time.
Nebeker:
I know the SAGE computer was a landmark in the history of computing. How did that work go?
Stotz:
Well, that work went well. When the contract started, we sent about 30 people up to Poughkeepsie for three weeks of training on IBM and IBM ways of doing things and the system and whatnot. So I went up there for three weeks. And when we got back, the head of the project called me in and said "you are going to teach a course in computers because none of these people know anything about computers. So you're elected to teach it."
Nebeker:
What was your background in computers at that point?
Stotz:
Just what I've told you. Why he thought I could do it I don't know. But anyway, I got a couple of books and I started in and I think I probably spent about two months before the first class. And I managed to stay a couple of weeks ahead of them through several months of once-a-week two-hour classes in computer science.
Nebeker:
So this is like general computing at the time, the state-of-the-art of computing and not specifically the SAGE computer?
Stotz:
No. I started with Boolean logic and switching circuits à la the telephone company and went through the whole thing about what is in a computer, what do these pieces do, a little bit on the rudiments of programming. Very little.
Nebeker:
That was in the mid fifties here?
Stotz:
That was 1955.
Nebeker:
Okay, so this is— I can't quite remember, but somewhere about there is FORTRAN and some of these other languages are being developed. Were you programming in Assembler language or machine code?
Stotz:
On that contract, we didn't do any programming at all.
Nebeker:
So it was just for your course that you were saying something about how to program the computers?
Stotz:
Yes. There was a book written by somebody from IBM that I used as a textbook. And that has a chapter on programming at the end. And that's what I used.
Nebeker:
So how did that go, teaching computer science?
Stotz:
Well, as far as I was concerned, I think it went all right. Unfortunately all of the people taking the course got busier and busier and the attendance dropped off to practically nothing toward the end. But I think the course served its purpose. I certainly didn't make a computer engineer out of anybody, but I learned a lot.
Nebeker:
Did it, did it mean that you were asked to do other teaching jobs at Bendix?
Stotz:
No. I don't think I ever taught anything else.
Nebeker:
Did you continue work on that SAGE system?
Stotz:
Actually I didn't really do very much on the system itself. I spent most of my time teaching that course. And when that was done, I think fairly soon I got pulled off onto something else.
Nebeker:
You list here the KY-4 secure communications system.
Stotz:
That came a little bit later. There was another aborted contract in there for a radar system for the Signal Corps that didn't go anywhere. But I worked on that for a little while. But, yes, I guess the next thing of any consequence was the KY-4.
Nebeker:
How was it as a young engineer working at Bendix? You've described getting different assignments and then some of them end rather suddenly and put on something else? How did it feel to you?
Stotz: Well, sometimes you'd like to see something through to the end, but you don't always get the chance. There was usually something interesting that came along. There were drought periods. I think I spent one period doing nothing but writing proposals for quite a while, most of which didn't result in contracts. But there were always little things coming along.
Nebeker:
You were doing some proposals even at that early stage?
Stotz:
Well, I was working on them, yes.
Nebeker:
So this was a larger project that that Bendix was proposing and you were asked to contribute?
Stotz:
Yes, some of these proposals are huge.
Nebeker:
How was it going for Bendix in those years?
Bendix
Stotz:
Fairly well. In those days, we were pretty well off in the government business. We were building car radios by the millions. And though home radios were pretty much down by the mid fifties we were still building TVs for a few more years. But by 1959, all of that work was gone.
Nebeker:
When you say home radios, do you mean like just ordinary radio receivers?
Stotz:
Yes, we built quite a lot of those ranging from little table radios, clock radios, up to consoles.
Nebeker:
Did Bendix get out of that business?
Stotz:
Yes. We were never very successful at it. I think we never quite mastered the commercial market.
Nebeker:
I know the clock radio was popular.
Stotz:
Yes. That wooden case with a handle on top, Model 753. One thing I've been doing at the museum is maintaining the database on all of this stuff. We own four of those clock radios.
Nebeker:
It seems to me it was General Electric that introduced the snooze button somewhere in the late fifties.
Stotz:
That could well be.
Nebeker:
You didn't have a snooze button on your Bendix clock radio?
Stotz:
I don't think so. I think it's a great invention.
KY-4 Secure Communications System
Nebeker:
Back to the KY-4 secure communication system. What was it?
Stotz:
It was a device for NSA to encrypt voice communications.
Nebeker:
A scrambler sort of system?
Stotz:
Yes. We had started on that probably about 1950 or so, built a model and tested it. And then they wanted a smaller, better one, so the project started up again in another department. And that's when I got into it sometime after that second program had started.
Nebeker:
Was this digital technology?
Stotz:
Yes. You use a device called a voice coder, which digitizes the voice. And then with a digital signal, you can encrypt it and decrypt it. And then through a simple D-to-A converter, you get the voice back.
Nebeker:
Was it was converted to a binary signal?
Stotz:
Yes. And from there on, it's standard cryptographic techniques. The problem was that when you take a 3-kilohertz voice signal, put it through a vocoder, you get around a 30-kilohertz signal. And the radio transmission that you're using suffers because you've now increased the bandwidth significantly, so you've reduced the range. We told them that way back and they didn't want to believe it until we finished several prototypes and they took them out to Arizona and tested them and found out we were right. And that was the end of the program.
Nebeker:
Oh. So that would not do for the application they had in mind?
Stotz:
No. The range of the radio was reduced below what they could tolerate.
Nebeker:
That's fairly early for a digital system.
Stotz:
It was the late fifties.
Nebeker:
Do you remember that being challenging?
Stotz:
Not terribly. Again, the customer told us a lot of the things we needed to do. The biggest challenge with that was the size and the subminiature vacuum tubes that it used.
Nebeker:
Because this had to be a field radio for use with a walkie-talkie or something like that?
Stotz:
Actually the radio in question was Jeep-mounted. So this thing mounted on a Jeep and had to withstand all of the usual military stresses.
Nebeker:
So you had to design it to be very rugged.
Stotz:
Yes. We were pretty good at that by that time.
Nebeker:
Because of your experience with car radios?
Stotz:
It was very different from car radios. Actually the car radios were off in another part of Bendix. And the first car radio had some of the engineers from the military side in 1948 for the '49 Ford, but very quickly that became a completely separate operation with their own engineers.
Nebeker:
Was that when Bendix got into car radios?
Stotz:
Yes. Yes, we built over half of Ford's radios in that period.
Nebeker:
Oh. Were you ever involved in that?
Stotz:
No.
Nebeker:
Why would a Jeep radio be significantly different from a car radio?
Stotz:
Because of the mechanical requirements, the shock and vibration.
Nebeker:
It's just so much greater on the Jeep?
Stotz:
It can be.
Nebeker:
So you had to build it so it's going to continue to function.
Stotz:
And car radios had tubes in them. They had vibrators, which are not particularly rugged. So the military specs are just totally different.
Aircraft Collision Avoidance System
Nebeker:
What was your next project when that project ended in the late fifties?
Stotz:
Yes, I guess the next major thing I got into was aircraft collision avoidance.
Nebeker:
Oh. Is this a radar system?
Stotz:
No. Going back to the beginning: sometime in the early fifties, there was an aircraft collision over the Grand Canyon that you may remember hearing about. Two large aircraft collided over the canyon and killed I don't know how many people. The next morning, our general manager got a phone call from the Air Transport Association saying "please help us. We've got to do something about this." And that day, they convened a meeting of eight or ten engineers. I think I was included because I wasn't doing anything else at the time. A mathematician in our R&D department named Dr. Morrel was sort of in charge. He had been working on collision problems from a mathematical viewport for some time. We spent most of that week debating what kind of system could be built, whether it was practical in the first place, and particularly whether you could build a system that was completely self-contained in one aircraft. And we concluded you couldn't with the technology available then. Dr. Morrel kept on working and some other people kept on thinking about it. In 1957, I think, we got a contract from the Air Force to study and devise some sort of a collision avoidance system. And we came up with a design, which looked like it might work, and got another contract to build an experimental model of it and test it.
Nebeker:
How did that system work?
Stotz:
It had a transmitter in one airplane that transmitted a signal, which had its altitude and its identification coded in it. And that signal was received by another airplane by a direct path and by another path bouncing off the Earth and back up to the airplane. There was also a time signal in it, and by measuring the difference in time, you could, on successive pulses transmitted over time, make a calculation of whether you were in danger of colliding.
Nebeker:
So this is being done at a standardized frequency that all of the systems would be locked on.
Stotz:
Yes. I don't remember the details of it, but it involved a receiver and a transmitter and a signal processing box.
Nebeker:
I see.
Stotz:
And after they had gotten the design of these things pretty well figured out and underway, they decided they needed some kind of a computing device to take the output of this box and calculate whether or not they're going to collide. And I got the job of building that computer, which kept me busy for the next year or so.
Nebeker:
How did that go?
Stotz:
It worked. It was a very strange computer.
Nebeker:
This was before integrated circuits, so you were working out these circuits?
Stotz:
Yes. We had been building circuit modules for NSA, which are little plastic things with wires sticking out the bottom. And in there were two circuit boards with notches in the sides and components stuffed into those notches, transistors, resistors, capacitors, whatever. And there were all kinds of modules for various digital functions, flip-flops, AND gates, OR gates, all of that.
Nebeker:
And these were all of the little modules that you worked with?
Stotz:
Yes. And those get soldered into circuit boards. And that's what this computer was built from.
Nebeker:
What was the magnitude of this? How many modules were required?
Stotz:
Oh, I don't remember how many modules there were.
Nebeker:
Are we talking about dozens?
Stotz:
Yes, dozens at least. Maybe over 100. It used a magnetic drum for storage. And it was a very primitive computer in terms of how computers are built. Part of it was parallel and part of it was serial to multiply the numbers we were working with, some of the numbers were fixed. We knew what they were. So we could put those individual bits in strategic places around the drum and put the multiplier there and the number you're multiplying in a register and shift the two together. It was very primitive. I think it could execute 64 instructions, in total. And the program was set up on a plug board. But it did the job. We installed the system in a DC-3 and we flew that against another airplane. And we ran tests over flat country and over the mountains and over the ocean and it was able to determine the threat of collision.
Nebeker:
So it would give a warning if there's a danger of collision. These would just be on all the time?
Stotz:
Yes. It told you to go either up or down.
Nebeker:
Oh, it actually made that decision?
Stotz:
Yes. It couldn't tell you whether to turn because it's almost impossible to tell which way to turn. If you're flying along and another airplane is flying toward you and you're watching him and he's getting closer and closer, you don't know whether to turn left or right. You can't tell until he's too close.
Nebeker:
And how do you be sure that both planes don't do the same thing, like go up to avoid collision?
Stotz:
The altitude is encoded in the signal and the one on top goes up and the other one goes down. Anyway, we demonstrated that this system was feasible. And then the FAA decided that with the beacon system they were installing and requiring all of the airplanes to carry, you didn't need it. They would have such tight control over everybody that they didn't need collision avoidance, so they dropped the program. Then years later, other people at Bendix and other places started working on the problem again. And that resulted in the BCAS system and then the TCAS system, which is in use in all airplanes today. And the collision criterion that Dr. Morrel had developed in the mid fifties is still the heart of that system. The method of measuring is totally different. I never had anything to do with those later contracts, so I don't really know much about that.
Nebeker:
Did it disappoint you that that this system didn't go into use?
Stotz:
Well, yes. We would like to have gone on and gotten the system into production. We did get a patent on it.
Nebeker:
I was going to ask if there were publications or conference presentations on any of the work that you were doing.
Stotz:
There were. Dr. Morrel talked all over the world about it actually. He was really the expert on the subject. And he appeared at ATA and IATA meetings and what not all around.
Independent Research and Development on Communications Systems
Nebeker:
So that was the collision avoidance system in the early sixties. And then you had digital communications systems, and what was the IR&D project?
Stotz:
IR&D means independent research and development. You are allowed to get a certain percentage of money in government contracts to do with what you want. And we had a variety of things like that. I worked on a fair number of them. None of them ever really amounted to much in terms of products, but I spent a fair amount of time just working on projects of that kind that didn't really result in products and we were looking for things that might.
Nebeker:
But it sounds like that's a very nice assignment for an engineer to be able to explore some possibilities.
Stotz:
Yes, it is. It's interesting. You get an idea, you write a proposal for the project, and if it gets approved, then you work on it for six months or whatever. Every year they fund a bunch of these things.
Nebeker:
Is the competition stiff?
Stotz:
Not really. It depends on how many people there are that don't have a whole lot else to do. Sometimes you're so busy that there's no time for this kind of thing.
Nebeker:
Are there any of those projects that stick in your mind as being especially interesting?
Stotz:
Not really. I sort of tend to forget what they were.
Nebeker:
Were these communications systems?
Stotz:
Yes. The ones that I was involved with were in the general area of digital communications. Things like multiplexors.
Nebeker:
This is fairly early for digital communications.
Stotz:
Yes, compared to what's happened since it was very primitive.
Nebeker:
And AT&T was beginning to move in that area in the late fifties and the early sixties.
Stotz:
Their big thing in that period was the electronic switches. That's where a lot of their effort went. But, of course, we weren't really involved in anything like that. The department I was in was involved with a lot of digital devices for military communications where there was a specification—I have no idea what the date of it was, but it was somewhere in that period—Mil-standard-188 that required a complete revamping of all of the military's teletype communications.
Nebeker:
For security reasons?
Stotz:
Yes. Instead of whatever the standard teletype signal was, 60 volts or something like that, it required a plus and minus 6-volt signal and very small current. The head of the department I was in at the time had worked for them and knew all about this stuff. And he started us developing various devices to meet these requirements. One of them, for instance, was a keyer that went in a teletype machine that would take the signal that would normally be generated and produce it as a plus and minus 6-volt signal instead. And on the other end, something that would take that signal and drive the mechanism of the teletype. And there were various things that were used in between. And we built power supplies for those and the biggest thing we did was a teletype router, a thing to route teletype messages. That was a fairly big digital box. And I had some contact with those things, but mostly there were other people doing those. But we produced quite a lot of hardware of that type.
Reflection on Work for Bendix Radio
Nebeker:
How was it going for Bendix Radio in the sixties and early seventies?
Stotz:
There were ups and downs. There were slow periods and there were periods that were quite busy.
Nebeker:
Did you ever fear for your position?
Stotz:
Occasionally. The one big thing that they were doing in the early sixties, beginning in the late fifties on the radar side was the phased array radar. And I had nothing to do with that until we did get a project in connection with the FPS-85 that they were putting together in Florida. That's a large phased array radar for tracking things in space. A lot of it was built and then it caught fire and burned to the ground and then they built it again. And it went into service about 1970 or so and is still in service.
Nebeker:
This is for tracking spacecraft?
Stotz:
Yes, it's a building about 15 stories high, 300 feet long, with a 45-degree face on it with a transmitting antenna on the one end and then a receiving antenna on the other end. That sits there and tracks thousands of things going by overhead. Anyway, before the fire, they got us to build a video integrator to try and get the noise figure of the receiving system up a little bit. It wasn't quite up to spec. And so we built a video integrator using magnetostrictive delay lines, about three racks full of hardware. And it was down there being tested, checked out, when the fire occurred. When they rebuilt it after the fire, they were able to buy receiver diodes with a 1/2-dB better noise figure, so they didn't need the video integrator.
Nebeker:
Yes, it's very interesting. Outsiders don't realize how much of development doesn't lead to products. Conditions change and new technologies come along and provide a different solution to something.
Stotz:
[Interposing] Very true. It happens all the time.
Nebeker:
Were you happy with your work at Bendix in those years?
Stotz:
Yes, generally.
Nebeker:
I see you got into reliability engineering in the mid seventies.
Stotz:
Yes, that was a case of downsizing and they didn't have anything else to do with me so they put me into reliability, which was another subject I knew nothing about.
Nebeker:
But you were good at taking up new subjects.
Stotz:
Well, I don't know about that that. I had dealt with these people and I knew they got information from us and went off and did things and told us whether we met the specs. But how they did it or just what they did, I knew nothing about.
Nebeker:
So how did that go, going to reliability?
Stotz:
Well, I didn't really care for it. I learned the rudiments of it. I worked on the reliability for the MLS Microwave Landing System program.
Nebeker:
What was that program?
Stotz:
It was a system to replace the standard ILS glide slope landing using microwave signals. The FAA started a program on that. There were two competing systems. I think there were originally eight companies in it, four of them working on one system and four of them working on another. And then they narrowed it down to two on each and then one on each and finally they chose between the two systems and we won. We had been using a phased array system as opposed to a scanning beam. We went on to get this accepted by everybody and it was about to the point where it would start to take off and then we installed a few systems in places like Valdez, Alaska and Lake Tahoe in California, places that were particularly difficult to land in because of mountains. And then the system was pretty much abandoned because everybody thought GPS was going to solve all of the problems. And someday it will, but it hasn't yet.
Nebeker:
So you were doing reliability on that.
Stotz:
In the early stages of the design of that, yes. I was doing reliability for maybe a year. And then and then I got off onto another thing.
Nebeker:
Reliability testing again?
Stotz:
No, actually this was the Patriot Missile database. That was started in the reliability department. I am not quite sure why. But I got into that and we set up a fairly elaborate database system to track all the production information about the Patriot Missile fuse. We were building fuses for the missiles for Harry Diamond Laboratory. They wanted to have a complete history on every component in it and all of the test data and all of the steps in assembly.
Nebeker:
So they were tracking every piece in every missile?
Stotz:
Every piece in this fuse, just in the fuse. It had a bunch of circuit cards in it. It had hybrid circuits, and there was a lot of stuff in it.
Nebeker:
So that's like some kind of proximity fuse that detonates the missile?
Stotz:
Yes. And they wanted a complete history of everything in it.
Nebeker:
Was that unusual? It sounds excessive.
Stotz:
Yes, I think it is. I never knew any other project that did it. But we had a record for each piece when it came in and where it went, what assembly it went into. And for that assembly there was a record. If the component was replaced, we had replacement records. And then the test systems generated data, which went into the database. So you could go in there and find what was the voltage on this transistor at this point in the test procedure, you know, and all of that sort of thing, hundreds of data points. I'm not sure it was worth the effort, but they seemed to think it was.
Nebeker:
So what was your job? Were you in programming on that?
Stotz:
I was pretty much running the database. We bought database software, and a man from that company set up the database for us. We explained to him all of the things it had to do and he wrote the description of the database. Then I pretty much managed it from there. Again, back in those days things were a little different than they are now. This was 1980 and '81 and '82 when it started. The process of updating the database meant you fed in a file and it ran for a couple of hours and then you fed in another file. That updated the data and then another file updated the index, and another file updated the range index. Then you went through all of this process once every night. I had a computer terminal at home and I would log into the system at work and run the procedure that did all of this. And I had to write some of these procedures. This was all done on a VAX computer.
Nebeker:
How did that work go?
Stotz:
It worked fine. We started out in the engineering department's VAX and they decided we were getting too big for them and were going to throw us off, so we had to get our own.
Nebeker:
You said you had to do this updating at night?
Stotz:
Yes. The people would be typing into computer files during the day, and then I'd take those files and run them at night. And I did it from home so I didn't have to be there.
Nebeker:
What kind of a terminal did you have at home?
Stotz:
Oh, just a simple computer terminal vintage 1980. I forget who made it.
Nebeker:
This is not a teletype terminal. This is a CRT of some kind.
Stotz:
Yes, it was a CRT.
Nebeker:
And the database did what it supposed to do and?
Stotz:
Yes. We never succeeded in getting the people on the program to make a whole lot of use out of it, at least not while I was still there, but it recorded what it was supposed to and it was available. And the object of a database is to put information in in a form that it can be got out in any way you want. And it did that. I run a database down at the Museum of Industry with this Bendix stuff and we keep putting stuff in and occasionally we look at it.
Nebeker:
So it's good you have a background in databases.
Stotz:
I guess I got that job because I had. Also I owned a program that could be used.
Nebeker:
It looks like you were on that for quite a few years.
Stotz:
Yes. Longer than I might've liked.
Nebeker:
How was it going with Bendix Radio in those years, in the eighties?
Stotz:
It was going reasonably well. I think we had lost the radar business by then. The FPS-85 was the last real radar that we built. And we kept getting outbid on others so the radar side sort of petered out.
Nebeker:
What were the main activities of Bendix Radio in those years?
Stotz:
Let's see. IFF was a big thing. Secure communications was big, some communications work other than secure communications, and there were a few other odds and ends, like a precision runway monitor system. Again, it was a neat system and worked like a charm, but we never sold very many of them. If you had parallel runways in an airport, the normal requirement is they have to be at least a mile apart in order to land planes simultaneously. With this, you could reduce that to at least 4,000 feet and maybe less because you had a display that showed you exactly where every plane was. And the controller could tell what was going on and guide them.
Nebeker:
Were you ever involved in dealing with customers and potential customers in selling the products?
Stotz:
Yes. Not as much as some. There were some engineers who did a lot more of that than I did.
Nebeker:
[Interposing] So you were sometimes making presentations at these companies.
Stotz:
Yes. Going to answer questions and find out what their problems were.
Nebeker:
Did you have any other assignments before retirement?
Stotz:
No, not really. I pretty much stayed with that Patriot thing.
Retirement
Nebeker:
So when did you retire?
Stotz:
April 1992.
Nebeker:
We always like to ask if the engineers have had hobbies or other interests that they care to mention.
Stotz:
Not really, not much.
Nebeker:
Well, I know you have a little interest in history.
Stotz:
Yes, I do have an interest in history. I read a lot.
Nebeker:
And what is this museum?
Stotz:
About ten years ago, five retired engineers were talking one day and thought "gee, it'd be a good idea if we could gather together some of this Bendix material and sort of save it for posterity." This was shortly after AlliedSignal had sold the division to Raytheon in 1998. So somehow—and I'm not sure how—they got in contact with the Baltimore Museum of Industry and suggested maybe they could cooperate in some way. And the museum thought it was a good idea. So they started in. And I guess they asked everybody they knew for any material they might have. There is a group of engineers that meet for lunch every month. And I think there's something like 80 or 90 people on that list. They probably get around 30 at any given meeting.
Nebeker:
These are all Bendix engineers?
Stotz:
Yes.
Nebeker:
Is that something you have gone to?
Stotz:
I haven't lately, but I did for a while. So they are all aware of what's going on. They contribute things. And there's another group of retired employees, not just engineers, but everybody, that's been meeting for lunch once a year. That was close to 200 people at one time. It's down to probably about 100 now. We make a pitch to them every year and we get stuff from them. And we have memberships in the organization where you contribute $25. Ten dollars goes to the museum for a membership in the museum and we get the other $15. I think we currently have about 120 members in that group. But anyway, a few people got more involved in it. And I think it had been going for almost two years before I got into it. We meet every week. At first it was just gathering stuff. In 2002, we put together an exhibit, which occupied one large area of the museum. I think we had 20 4-by-4-foot panels, each on a different subject, covering various product lines and other aspects of the business. And we had four or five cases of artifacts. That stayed up for three-and-a-half years, much to our surprise.
Then we had a couple of small exhibits, specific exhibits, in part of the entranceway into the museum. One had to do with the sinking of the Bismarck in World War II. The Bismarck had been launched and commissioned in the port in Hannover or Bremen, I forget which. It was trapped there, and they decided they would try and get it out. So they did. The British Navy found it was loose and they started chasing it and they chased it around the North Atlantic for a week and damaged it. The Bismarck was trying to get back to some port in Europe and a British airplane, a spotter plane, saw it and radioed its location. And the whole point of this was that they used a Bendix transmitter. And we have one of those transmitters.
Nebeker:
Very nice.
Stotz:
And we have the ad that they put out about that time that has a cablegram from the British Admiralty congratulating us on the high quality and reliability of our transmitter that allowed them to sink the Bismarck. So we built an exhibit around that.
Nebeker:
Sounds good.
Stotz: It was up for about a year. And then after that we put up one of home radio and TV. That was there for I guess a year. And now we have just built a new permanent exhibit in another location that covers everything. One of the things in it I was just talking to Mike Simons about just now is an SCR-522 aircraft radio from World War II that we borrowed from the National Electronics Museum here. We built thousands of them for the British and ourselves. And virtually every Allied aircraft in World War II had one. But we didn't, so we had to borrow it.
Nebeker:
Oh, that's very admirable work you're doing on preserving those, those artifacts and those memories.
Stotz:
Well it keeps us off the street.
Nebeker:
Is there anything that I haven't asked about that you'd care to comment on?
Stotz:
Can't think of anything.
Nebeker:
Thank you very much for taking the time and sharing your interesting memories.
Stotz:
Well, I'm glad to do it.
